The present invention relates to heat pump systems, and particularly to the utilization of a unitary or integrated fluid motor and compressor, such as a turbine and compressor, in a single fluid system. Heat pump systems are well known, particularly for space heating and cooling, and the present invention is described herein in that context. However, it should be understood that the invention is also applicable to other environments, such as vapor compression evaporators.
The present invention is described herein with reference to a combined turbine and compressor, wherein the fluid output flow from the turbine and the compressor are combined into a single mixing chamber or volute. By means of this invention the efficiency of heat pump systems is significantly improved. Although it is currently envisioned that a turbine/compressor unit is the preferred form of practicing the invention, it is not intended that the invention be viewed as limited thereto.
Single fluid heat pump systems are known in the prior art, as exemplified by the U.S. Pat. Nos. to N. C. Rice, et al. 3,259,176 and A. B. Steuart 1,871,244. The working fluid for such systems may include a fluorocarbon refrigerant, as suggested in the Rice patent, or may be water, ethanol, methanol, or the like, or mixtures thereof. These systems include: one circulating subsystem wherein liquid working fluid is fed to a boiler and vaporized under pressure, expanded through a turbine, condensed back to a liquid in a condenser, and cycled back to the boiler; and a second circulating subsystem wherein said liquid working fluid is fed to an evaporator where it is expanded to a vapor, compressed in a compressor driven by said turbine, condensed back to a liquid in the same condenser as stated above, and recycled to the evaporator. There are thus provided two parallel subsystems, wherein the turbine of one, drives the compressor of the other, and the outputs of the turbine and compressor are combined into a single flow feeding into a single condenser. In the prior art systems, the turbine and the compressor are separate and individual units possessing their respective individual input and output chambers or volutes, even though they have an interconnecting drive shaft, and even though they may be combined within a single casing or housing, as suggested in said Steuart patent.
In accordance with the present invention, the turbine/compressor has a single rotor carrying two sets of blades, one set for the compressor and one set for the turbine, each set of blades having its separate input chamber or volute. However, the outputs for the two sets of blades feed into a single output mixing chamber or volute. It is through the provision of this single output of mixing chamber that the improved efficiency of the present invention is obtained. Whereas the prior U.S. Pat. No. 2,238,502 to Muir discloses a turbine/pump combination wherein the output of the turbine and the output of the pump are combined in a single chamber, there is no teaching or suggestion that such a unit would increase the efficiency of a single fluid heat pump system of the type stated above.
Accordingly, it is one object of the present invention to provide a heat pump system having improved efficiency.
Another object of the present invention is to provide a single fluid heat pump system having improved efficiency.
Still another object of the present invention is to provide a combined turbine/comressor for improving the efficiency of a single fluid heat pump system.
And a further object of the present invention is to provide a combined turbine/compressor having a single output mixing chamber or volute for improving the efficiency of a single fluid heat pump system.
Other objects and advantages of the invention will become apparent to those skilled in the art from a consideration of the detailed description of one embodiment of the invention presented hereinafter to facilitate a complete understanding of the invention. It is understood, however, that the specific embodiment disclosed is only illustrative, and other embodiments will be apparent to those skilled in the art.